Zapping the brain's 'mu' waves may cure autism

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Oct 26, 2006, 12.00 AM IST

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The marriage of yoga with flower power in the 1970s led to techniques such as biofeedback and relaxation response. Alpha biofeedback has been popular ever since with increased alpha waves being reported among practitioners of Yoga and Zen.

It has taken scientists 30 years to come up with a more practical application: they are now talking about a possible ‘cure’ or amelioration of autism based on the control of a normal variant of the alpha brainwave called mu. The mu wave is seen over the motor cortex, which is located beneath the central scalp.

It disappears with movement, or even with the intention to move and when you watch other people move without making a movement yourself. But, this does not happen in autistic individuals, say researchers from the University of California, San Diego.

The brain circuits that enable people to perceive and understand the actions of others behave abnormally in such individuals. These circuits are based on special nerve cells called mirror neurons. Discovered in the 1990s, mirror neurons are believed to be vital to a variety of functions ranging from language and learning to empathy and social interaction.

EEGs of ten ‘high-functioning’ subjects (having an age-appropriate vocabulary and IQs above 80) were taken in the study, along with an equal number age and gender-matched control subjects. Their brain waves were recorded while they moved their own hands and while they watched videos of visual noise, and balls bouncing and a moving hand, respectively. As expected, mu wave suppression was reported in the control group.

In contrast, the mu wave remained unaffected when autistic subjects watched movements of others. Only when they moved their own hands did the wave disappear as expected. The scientists cite this as the first experimental evidence of an impaired mirror neuronal circuit involved in autism, which may point the way to early diagnosis and also to potential therapies: doctors could set up a biofeedback loop based on an autistic child’s mu waves.

If his mirror neuron functions are dormant rather than completely lost, says the noted neurologist VS Ramachandran also involved in the research, it may be possible for him or her to revive this ability by learning—through trial and error and visual feedback—how to suppress the mu waves on the screen.

Dr Ramachandran’s colleague, Jaime Pineda, director of the Cognitive Neuroscience Laboratory, is pursuing the mu-feedback approach and his preliminary results appear to be promising. He says we can learn to increase or decrease the strength of the mu signal at will.

By imagining action, subjects are able to move a paddle in a computer game of ‘Pong’ after just four to six hours of practice. Because this rhythm is one that we have access to volitionally, it could prove useful in therapy.

But, such therapies should supplement rather than replace the traditional behavioural-training techniques, Dr Ramachandran suggests. PsychoBabble envisions the intriguing possibility of hyping up our social intelligence by conditioning the mu-zapping ability of the brain.

(This article was originally published in The Times of India)

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